Still, Lehrer's example, as the guy lambasted across media for losing control of last week's debate between Democratic President Barack Obama and GOP challenger Mitt Romney, may offer some sobering tips.

Already, Raddatz is taking a bit of flak, as The Daily Caller website published a story Wednesday noting Obama attended the correspondent's 1991 wedding to Julius Genachowski, her second husband, suggesting a conflict.

Genachowski, an Obama appointee to head the Federal Communications Commission, was a member of the Harvard Law Review with Obama. He and Raddatz divorced in 1997; both of them have remarried, leading ABC News to call the story "absurd."

But that piece and the criticism Lehrer faced — Saturday Night Live showed the semiretired PBS anchor zoning out during a parody skit — also demonstrated how much scrutiny moderators face in today's media world.

"The stuff about me is minor . . . the public understood it from the very beginning," Lehrer insisted in an interview with the Tampa Bay Times this week, saying critics of his debate performance didn't get the goal of the new rules.

"The whole point of the exercise from Day One was to get these candidates to challenge each other," he said. "For the first time in the history of American politics, an American president and challenger went head to head."

Last week, the rules split the 90-minute debate into six 15-minute segments, with two minutes allowed for each candidate to answer the moderator's initial question and open discussion following. Tonight's rules are similar, though the debate is divided into nine 10-minute segments.

As Lehrer discovered, the candidates increasingly began jumping into open discussion for as long as they wanted. Critics said it allowed both men to make arguments that weren't quite true, focusing on a narrow set of topics.

"At first, it was a little disconcerting," Lehrer said. "Usually, when I talk to a candidate, they hush. But I realized, 'My God, they're talking to each other.' People may say it went off track, but I loved where that track was going."

If Lehrer has any advice, it's in what he regrets: not defining complex terms for the audience and not explaining the goal of the format.

Well aware he already has reversed one prediction that he'd never lead another debate, the 78-year-old anchor would say only, after hosting 12 debates, "never could I imagine doing another one of these. . . . I think this is a terrific one to go out on."